Here’s what I wrote in my case comment on the Ontario Court of Appeal’s decision in Momentous.ca v. Canadian American Association of Professional Baseball, Ltd::

“What is remarkable about the Momentous.ca appeal decision is not the result. The arbitration and forum selection clauses were both valid and enforceable and the plaintiffs should have litigated in North Carolina. Rather, the Court of Appeal’s reasoning is quixotic when minimizing the defendants’ attornment. Consent may be explicit or implicit; voluntary or involuntary; informed or uninformed.

In any case, giving consent has consequences. In Momentous.ca, the defendants’ attornment by defending on the merits constituted waiver and estoppel. In other words, while the defendants may have consented to another jurisdiction contractually, the deliberate act of defending the plaintiffs’ action in Ontario equates to waiver of its original choice.

The implications are two-fold.

First, when a defendant consents to the Ontario jurisdiction by submission or attornment, it concedes jurisdiction simpliciter and should not be permitted to rely upon a forum selection/exclusive jurisdiction clause or arbitration clause based upon its post-contractual conduct. Second, the defendant may still move to stay the proceedings based upon forum non conveniens.

In this way, the contractual principles, which inform consent-based jurisdiction, remain intact.”